Signaling details of network coded transmissions

Abstract

Methods, systems, and devices for wireless communication are described. A network entity (e.g., a roadside unit, a relay node, a user equipment (UE), or a base station) may use a network coding indication in a transmission that indicates the transmission is a network coded transmission (i.e., the transmission includes retransmitted packets from UEs in a wireless communications system). The indication may be explicitly or implicitly signaled in control information. For example, control information may include a field that explicitly identifies the network coded transmission. Additionally or alternatively, the control information may implicitly identify the network coded transmission, such as by indicating a format of control signaling or including a special source identifier in the network coded transmission. The network coded transmission may also include one or more network coding parameters that identify parameters of the original transmission.

What is claimed is: 
     
         1 . An apparatus for wireless communication at a first device, comprising:
 a processor;   memory coupled with the processor; and   instructions stored in the memory and executable by the processor to cause the apparatus to:
 receive, from a second device via a sidelink connection, a first transmission that includes an indication that the first transmission is to be encoded at the first device for retransmissions; and 
 transmit, via the sidelink connection to a third device, a second transmission that is encoded based at least in part on the indication, the second transmission comprising at least the first transmission. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:
 transmit, in response to receiving the first transmission, an encoding indication in a sidelink control information message, a medium access control (MAC) header, a MAC sub-header, or any combination thereof, wherein the second transmission is encoded further based at least in part on the encoding indication.   
     
     
         3 . The apparatus of  claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:
 transmit, in a first sidelink control information message, a format indication for a second sidelink control information message, wherein the second transmission is encoded further based at least in part on the format indication.   
     
     
         4 . The apparatus of  claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:
 transmit signaling comprising a source identifier, wherein the second transmission is encoded further based at least in part on the source identifier.   
     
     
         5 . The apparatus of  claim 4 , wherein the source identifier comprises a device identifier associated with the wireless device. 
     
     
         6 . The apparatus of  claim 1 , wherein the second transmission identifies a set of one or more transmissions encoded in the second transmission, the set of one or more transmissions including the first transmission. 
     
     
         7 . The apparatus of  claim 1 , wherein the second transmission identifies a first identifier and a second identifier associated with the first transmission, the first identifier corresponding to the second device and the second identifier corresponding to the third device. 
     
     
         8 . The apparatus of  claim 7 , wherein the second transmission comprises a first set of one or more bits associated with the first identifier and a second set of one or more bits associated with the second identifier. 
     
     
         9 . The apparatus of  claim 8 , wherein the first set of one or more bits and the second set of one or more bits are included in a sidelink control information message associated with the first transmissions. 
     
     
         10 . The apparatus of  claim 1 , wherein the second transmission identifies one or more transmission parameters associated with the first transmission. 
     
     
         11 . The apparatus of  claim 10 , wherein the one or more transmission parameters comprise a cast type, a feedback type, a hybrid automatic repeat request identifier, a location of the first UE, a communication range, a slot index, an index relative to the second transmission, a transport block cyclic redundancy check value, a transport block size, or any combination thereof. 
     
     
         12 . The apparatus of  claim 10 , wherein the one or more transmission parameters are included in a sidelink control information message associated with the first transmission. 
     
     
         13 . The apparatus of  claim 1 , wherein the first device comprises a roadside unit, a relay node, a user equipment, a base station, or any combination thereof. 
     
     
         14 . An apparatus for wireless communication at a first device, comprising:
 a processor;   memory coupled with the processor; and   instructions stored in the memory and executable by the processor to cause the apparatus to:
 monitor for a first transmission from a second device via a sidelink connection; 
 receive, from a third device, an encoding indication associated with the first transmission; 
 receive a second transmission from a third device; and 
 decode the second transmission based at least in part on the encoding indication to obtain the first transmission. 
   
     
     
         15 . The apparatus of  claim 14 , wherein the instructions to receive the encoding indication are executable by the processor to cause the apparatus to:
 receive the encoding indication in a sidelink control information message, a medium access control (MAC) header, a MAC sub-header, or any combination thereof.   
     
     
         16 . The apparatus of  claim 14 , wherein the instructions to receive the encoding indication are executable by the processor to cause the apparatus to:
 receive, in a first sidelink control information message, a format indication for a second sidelink control information message, wherein the format indication comprises the encoding indication.   
     
     
         17 . The apparatus of  claim 14 , wherein the instructions to receive the encoding indication are executable by the processor to cause the apparatus to:
 receive signaling comprising a source identifier, wherein the source identifier comprises the encoding indication.   
     
     
         18 . The apparatus of  claim 17 , wherein the source identifier comprises a device identifier associated with the wireless device. 
     
     
         19 . The apparatus of  claim 14 , wherein the second transmission identifies a set of one or more transmissions encoded in the second transmission, the set of one or more transmissions including the first transmission. 
     
     
         20 . The apparatus of  claim 14 , wherein the second transmission identifies a first identifier and a second identifier associated with the first transmission, the first identifier corresponding to the first device and the second identifier corresponding to the second device. 
     
     
         21 . The apparatus of  claim 20 , wherein the second transmission comprises a first set of one or more bits associated with the first identifier and a second set of one or more bits associated with the second identifier. 
     
     
         22 . The apparatus of  claim 21 , wherein the first set of one or more bits and the second set of one or more bits are included in a sidelink control information message associated with the first transmission. 
     
     
         23 . The apparatus of  claim 14 , wherein the second transmission identifies one or more transmission parameters associated with the first transmission. 
     
     
         24 . The apparatus of  claim 23 , wherein the one or more transmission parameters comprise a cast type, a feedback type, a hybrid automatic repeat request identifier, a location of the second UE, a communication range, a slot index, an index relative to the second transmission, a transport block cyclic redundancy check value, a transport block size, or any combination thereof. 
     
     
         25 . The apparatus of  claim 23 , wherein the one or more transmission parameters are included in a sidelink control information message associated with the first transmission. 
     
     
         26 . The apparatus of  claim 14 , wherein the third device comprises a roadside unit, a relay node, a user equipment, a base station, or any combination thereof. 
     
     
         27 . A method for wireless communication at a first device, comprising:
 receiving, from a second device via a sidelink connection, a first transmission that includes an indication that the first transmission is to be encoded at the first device for retransmissions; and   transmitting, via the sidelink connection to a third device, a second transmission that is encoded based at least in part on the indication, the second transmission comprising at least the first transmission.   
     
     
         28 . The method of  claim 27 , further comprising:
 transmitting, in response to receiving the first transmission, an encoding indication in a sidelink control information message, a medium access control (MAC) header, a MAC sub-header, or any combination thereof, wherein the second transmission is encoded further based at least in part on the encoding indication.   
     
     
         29 . The method of  claim 27 , further comprising:
 transmitting, in a first sidelink control information message, a format indication for a second sidelink control information message, wherein the second transmission is encoded further based at least in part on the format indication.   
     
     
         30 . A method for wireless communication at a first device, comprising:
 monitoring for a first transmission from a second device via a sidelink connection;   receiving, from a third device, an encoding indication associated with the first transmission;   receiving a second transmission from a third device; and   decoding the second transmission based at least in part on the encoding indication to obtain the first transmission.